DESCRIPTION (Applicant's Abstract): This project aims to develop a social cognitive neuroscience approach to understanding the use of rationalization to exert cognitive control over emotion (a) by elucidating which cognitive and affective information processing mechanisms are used to rationalize preferences when making a self-threatening choice among alternatives, and (b) by studying the breakdown of these mechanisms due to brain trauma or aging to help understand their functioning in normal populations. Experiments 1-4 test the hypotheses that rationalization of attitudes takes effort and cognitive resources, evolves over time, may alter both cognitive and affective components of attitudes, and may be so complete as to render revised attitudes as automatically accessible as un-rationalized ones. Experiments 5-7 provide converging evidence in support of these hypotheses using brain damaged patients. Experiment 5 uses amnesics to test the hypothesis that rationalization can occur even when initial attitudes and the reason for changing them (a stressful decision) can't be recalled; Experiment 6 tests the hypothesis that the cognitive resources used to rationalize are being impaired after damage to the frontal lobe; and Experiment 7 tests the hypothesis that damage to brain areas used to evaluate the personal, emotional significance of a choice will limit motivation to rationalize. Experiments 8-11 extend the results of the first four experiments to the elderly to determine whether and how age-related declines in the flexible use of cognitive resources will impair rationalization.